IMMUNOLOGY AND SEROLOGY LESSON 2 LEC

C

Which type of immunity is nonadaptive, non-specific, and provides an immediate response upon exposure to a pathogen?
A. Adaptive immunity
B. Humoral immunity
C. Innate immunity
D. Cell-mediated immunity
E. Acquired immunity

B

What is the primary physical barrier of the external defense system that prevents the entry of microbes into the body?
A. Cilia
B. Skin
C. Mucociliary escalator
D. Lacrimal apparatus
E. Normal microbiota

D

Which of the following is considered part of the first line of defense in innate immunity?
A. C-reactive protein
B. Toll-like receptors
C. Complement system
D. Mucous membranes

E. Natural Killer cells

B

Pattern Recognition Receptors (PRRs) function primarily as:
A. Antibodies that clear antigens
B. Internal sensors for extracellular infection and pathogen recognition
C. Clotting factors that prevent blood loss
D. Enzymes that lyse bacterial cell walls
E. Hormones that regulate fever

C

Molecules found exclusively on microorganisms that allow the immune system to distinguish self from foreign are called:
A. Acute-phase reactants (APRs)
B. Anaphylatoxins
C. Pathogen-Associated Molecular Patterns (PAMPs)
D. Damage-Associated Molecular Patterns (DAMPs)
E. Major Histocompatibility Complexes (MHCs)

A

Which of the following is an example of a PAMP found in Gram-negative bacteria?
A. Lipopolysaccharide (LPS)
B. Zymosan
C. Peptidoglycan
D. Double-stranded RNA
E. Single-stranded DNA

C

Toll-like receptors (TLRs) located specifically within endosomes detect which type of microbial components?
A. Lipopeptides and flagellin
B. Peptidoglycan and zymosan
C. Nucleic acids (dsRNA, ssRNA, dsDNA)
D. Lipoteichoic acid
E. Mannan and F-proteins

D

Which Toll-like receptor specifically recognizes flagellin on flagellated bacteria?
A. TLR1
B. TLR2
C. TLR4
D. TLR5
E. TLR9

C

TLR9 is responsible for recognizing which of the following ligands? A. Double-stranded RNA
B. Single-stranded RNA
C. Unmethylated bacterial DNA / dsDNA
D. Lipopolysaccharide
E. Lipopeptides

E

Which Toll-like receptor functions uniquely by mediating anti-inflammatory responses?
A. TLR3
B. TLR6
C. TLR7
D. TLR8
E. TLR10

B

RIG-I-like receptors (RLRs) are intracellular receptors that detect:
A. Bacterial cell wall peptidoglycan
B. Viral RNA in infected cells
C. Fungal zymosan
D. Extracellular lipopeptides
E. Bacterial flagellin

C

NOD-like receptors (NLRs) assemble into multiprotein complexes called inflammasomes, which function to:
A. Secrete immunoglobulin A
B. Synthesize cholesterol
C. Activate apoptotic proteins and inflammatory responses
D. Promote clot dissolution
E. Neutralize bacterial exotoxins

C

Acute-Phase Reactants (APRs) are plasma proteins produced mainly by the liver whose concentrations change significantly within how many hours of infection or injury?
A. 1 to 2 hours
B. 4 to 6 hours
C. 12 to 24 hours
D. 48 to 72 hours
E. 5 to 7 days

B

What is the normal reference range for C-Reactive Protein (CRP) in human plasma?
A. 0.01 to 0.05 mg/L
B. 0.47 to 1.34 mg/L
C. 20 to 40 mg/L
D. 40 to 200 mg/L
E. 200 to 400 mg/L

C

CRP levels begin to increase within 4 to 6 hours after infection or trauma and typically peak within:
A. 12 hours
B. 24 hours
C. 48 hours
D. 72 hours
E. 96 hours

B

Which acute-phase reactant is transported by High-Density Lipoproteins (HDL) to infection sites and acts to recruit immune cells?
A. Alpha-1 antitrypsin
B. Serum Amyloid A (SAA)
C. Haptoglobin
D. Ceruloplasmin
E. Fibrinogen

B

Alpha-1 antitrypsin serves a protective role during inflammation by acting as a:
A. Opsonin for fungal spores
B. Plasma inhibitor of proteases
C. Chemoattractant for basophils
D. Iron chelator
E. Activator of the classical complement pathway

C

Deficiency in Alpha-1 antitrypsin primarily results in tissue damage to which organs?
A. Heart and kidneys
B. Brain and spinal cord
C. Liver and lungs
D. Spleen and pancreas
E. Stomach and intestines

A

What is the principal function of Haptoglobin during acute-phase responses?
A. Binding free hemoglobin to prevent oxidative tissue damage
B. Converting ferric iron to ferrous iron
C. Lyse bacterial cell membranes
D. Stimulate histamine release from mast cells
E. Transport copper throughout circulation

D

What is the normal reference range for Fibrinogen in plasma?
A. 10 to 50 mg/dL
B. 20 to 40 mg/dL
C. 40 to 200 mg/dL
D. 200 to 400 mg/dL
E. 500 to 800 mg/dL

B

Fibrinogen contributes to host defense during inflammation by:
A. Hydrolyzing viral capsids
B. Forming blood clots that act as a physical barrier to microbial entry
C. Inhibiting capillary permeability
D. Resetting the hypothalamic thermostat E. Binding free copper ions

B

Ceruloplasmin exerts its protective enzyme function by converting: A. Hydrogen peroxide to water
B. Ferrous iron (Fe2+) to ferric iron (Fe3+)
C. Fibrinogen to fibrin
D. Superoxide radicals to hydroxyl ions
E. Complement C3 to C3b

C

A disease characterized by decreased levels of Ceruloplasmin and accumulation of copper in tissues is:
A. Rheumatoid arthritis
B. Atherosclerosis
C. Wilson's disease
D. Rheumatic fever
E. Emphysema

B

The Latin cardinal sign of inflammation denoting "heat" is:
A. Dolor
B. Calor
C. Rubor
D. Tumor
E. Functio laesa

D

"Functio laesa" refers to which classic sign of inflammation?
A. Pain
B. Swelling
C. Redness
D. Loss of function
E. Local warmth

B

During the early stages of inflammation, which chemical mediator released by mast cells, basophils, and platelets induces vasodilation and increased vascular permeability?
A. Lysozyme
B. Histamine
C. Haptoglobin
D. Interferon-alpha
E. Cathepsin G

C

The process by which leukocytes squeeze between endothelial cells of capillaries to enter injured tissue is termed:
A. Opsonization
B. Chemotaxis
C. Diapedesis
D. Phagocytosis
E. Exocytosis

B

What is the primary initial step in the sequence of phagocytosis?
A. Engulfment / pseudopodia extension
B. Chemotaxis
C. Phagolysosome fusion
D. Digestion
E. Exocytosis of debris

B

The process of coating a pathogen with molecules (such as C3b or antibodies) to facilitate its recognition and ingestion by phagocytes is called:
A. Diapedesis
B. Opsonization
C. Degranulation
D. Apoptosis
E. Marginations

D

The cellular structure formed immediately when pseudopodia enclose a foreign particle inside a phagocyte is the:
A. Phagolysosome
B. Inflammasome
C. Endosome
D. Phagosome
E. Lysosome

A

Fusion of a phagosome with an intracellular lysosome results in the formation of a:
A. Phagolysosome
B. Peroxisome
C. Autophagosome
D. Granuloma
E. Centrosome

B

In the oxygen-dependent pathway of microbial killing, what metabolic event describes the rapid increase in oxygen consumption by phagocytes?
A. Respiratory acidosis
B. Oxidative burst
C. Anaerobic glycolysis
D. Membrane depolarization
E. Fermentation

C

Which enzyme catalyzes the generation of superoxide radicals (O2) during the oxidative burst?
A. Myeloperoxidase
B. Superoxide dismutase
C. NADPH oxidase
D. Catalase
E. Alkaline phosphatase

B

Superoxide ions produced during the oxidative burst are converted inside the phagocyte into:
A. Nitric oxide (NO)
B. Hydrogen peroxide (H2O2)
C. Hypochlorous acid (HOCl)
D. Hydroxyl radicals (OH)
E. Carbon dioxide (CO2)

C

In the oxygen-independent pathway, membrane depolarization leads to an influx of which ions into the phagolysosome?
A. Na and Cl
B. Ca2+ and Mg2+
C. H and K
D. Fe2+ and Cu2+
E. HCO3 and PO4^{3-}

B

Antimicrobial proteins present in lysosomes that disrupt bacterial cell walls in an oxygen-independent manner include:
A. CRP and SAA
B. Defensins and Cathepsin G
C. Fibrinogen and Haptoglobin
D. Histamine and Prostaglandins
E. Transferrin and Ferritin

C

Natural Killer (NK) cells are specialized lymphocytes that target and destroy:
A. Encapsulated extracellular bacteria
B. Free viral particles in blood plasma C. Virally infected cells and tumor cells D. Helminthic parasites in the gut E. Fungal spores in alveoli

B

NK cells participate in Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) by binding to targets coated with:

A. Complement protein C3b

B. Antibodies
C. C-reactive protein
D. Mannose-binding lectin
E. Lipopolysaccharides

B

Innate Lymphoid Cells (ILCs) are primarily situated at which body sites:
A. Bone marrow parenchyma
B. Mucosal sites
C. Deep cortical zones of lymph nodes
D. Thymic medulla
E. Vascular endothelium

C

Fever is induced when pyrogens act on which regulatory center in the brain?
A. Medulla oblongata
B. Thalamus
C. Hypothalamus
D. Hippocampus
E. Cerebellum

B

Systemic fever contributes to innate host defense by:
A. Decreasing white blood cell motility
B. Inhibiting the growth of certain microbes and accelerating body repair reactions
C. Neutralizing bacterial endotoxins directly
D. Increasing serum iron availability for bacteria
E. Suppressing interferon activity

C

Which chemical agent in perspiration functions as an antibacterial enzyme by breaking cell wall linkages?
A. Sebum
B. Pepsin
C. Lysozyme
D. Mucin
E. Bile

C

Fluid flow through the lacrimal apparatus serves to protect which body structure?
A. Nasal cavity
B. Oral mucosa
C. Eyes
D. External auditory canal
E. Urethra

A

Which of the following TLRs is localized to the cell surface and recognizes lipopeptides?
A. TLR1 B. TLR3 C. TLR7 D. TLR8 E. TLR9

C

Single-stranded RNA (ssRNA) of viral origin is recognized by which pair of endosomal Toll-like receptors? A. TLR1 and TLR2 B. TLR4 and TLR5 C. TLR7 and TLR8 D. TLR3 and TLR9 E. TLR2 and TLR6

b

TLR4 recognizes which specific component associated with Gram-negative bacteria?
A. Flagellin
B. Lipopolysaccharide (LPS)
C. Zymosan
D. Peptidoglycan
E. Double-stranded DNA

C

What structural property describes C-Reactive Protein?
A. Dimer
B. Trimer
C. Pentraxin (five subunits)
D. Single polypeptide chain
E. Tetramer

C

At what temperature is C-Reactive Protein easily denatured/destroyed in vitro?
A. 37°C B. 45°C C. 56°C D. 70°C E. 100°C

A

Which acute-phase reactant binds copper and converts ferrous iron to ferric iron?
A. Ceruloplasmin
B. Haptoglobin
C. Transferrin
D. Albumin
E. Fibrinogen

D

The Latin cardinal sign of inflammation "Rubor" corresponds to:
A. Pain B. Heat C. Swelling D. Redness E. Loss of function